華語文作為第二語言教學，牽涉到語言和文字關係的認知，引發語言基本結構即「本位」的討論。「詞本位」是當前對外華語文教學主流；「句本位」也在廣義的「詞本位」之中，兩者皆取法印歐語法學理。「字本位」學理針對目前本位教學產生的問題，強調漢字是華語基本語言單位。在理論方面，華語屬於漢藏語系，為單音節語言，以方塊為文字外形，重以字形帶字義，故在視覺上以「字」為最小語素單位，有別於以拼音為書寫方式的印歐語系，故其語法與教學方法應不盡相同。「字」的地位依「語言知識」和「語言交際溝通」有所區別；漢字的形、音、義三者相輔相成，具有「以字組詞」功能，可融合詞彙與漢字教學。「字本位」理據與教學實驗在大陸已有豐碩成果且在持續建構。臺灣的正體字較大陸簡化字更具有其學理優勢，可更積極建構其系列學理並落實於教學方法。

In the present, the teachers of TCSL (Teaching Chinese as a Second Language) principally adopt “word-based” approach and “sentence-based” approach as their basic principles. To base on the understanding of the different structures between Sino-Tibetan and Indo-European, this paper would like to clarify the definitions included “word-based”, “sentence-based” and “character-based”. It is quite obvious that both “word-based” and “sentence-based” approaches are useful on the one hand but insufficient on the other hand when they are applied to the real teaching occasions. Again, according to the experiment data offered by some scholars, this paper also indicates that “character-based” approach could advance the students’ Chinese degree effectively either speaking or reading. The conclusions are as follows: 1.“Character-based” approach is helpful to combine the highfrequency words and oral/written usage. 2.“Character-based” approach could improve the quality of present-day TCSL.3.Using traditional Chinese characters in TCSL is the competitive advantage of Taiwan teachers.